Flat black has been used in a lot of places that it shouldn't. IMO a rat rod and a low budget muscle car are the only places I think flat black really belongs. Unfortunately though, when I hear "flat black" now, the immediate correlation in my head is a spray-bombed civic with a fart can. And now Cadillac offers flat black on the new CTS for middle aged men that want to try to bond with their teenage punks.
Murdering out a bike or car (to me) is quickly becoming the
Nickelback of vehicle design. Way more popular than it should be, lacks creativity, and makes you look like the kind of guy that really wants a Harley but can't afford one. Take your time and think about what you really want. I feel that if you want to go with a lot of black, gloss is a better finish. Black always looks brilliant on bikes and compliments just about any other color you want to mate with it. But black, gloss or flat, as the one and only color just makes your bike blend in with the millions of other black bikes out there.
A good rule of design regarding paint schemes is to try to stick to 3 colors. Chrome, aluminum, metal doesn't count as one of the three. In the CB 400 above, Herrdeacon did a great job using red/white/black and tied it in nicely with the polished parts. My first bike is mostly black, black wheels, cases, frame, cylinder heads, handlebars, etc. The 2 fenders and tank are dark metallic brown and with a silver stripe. The brown and silver is enough to set it apart and give it its own identity. It's an unusual color choice I know, but I routinely get compliments on how people love the color scheme. If you like a lot of black, paint everything black but the tank. Be creative with your color choice/design on the tank, and since everything else may be black the tank will be the showcase of your bike.